1. Field of the Invention
The invention relates to transmitting service data to services controlling the processing of a communications connection in an intelligent network-like manner, and particularly to transmitting service data for non-standard services.
2. Description of the Related Art
Telecommunications network facilities can be divided into three different call processing levels: service level, call control level and switching level. The switching level serves to provide the physical connections (i.e. “media”). The call control level is responsible for routing a call to a correct destination and it controls the switching level. The service level serves to produce the subscriber's supplementary services and possibly also part of the basic service and controls the call control level. In the existing telecommunication networks, a typical facility comprising a supplementary service is conditional call forwarding in which the call situation must be analyzed and the call routed on in accordance with the stored call forwarding service profile.
An intelligent network IN is a network architecture to be attached to a basic network (a fixed or a mobile network, for example) enabling a feature to be divided into a service level and into an entity comprising a switching level and a call control level. The network node providing the intelligent network access is usually the network node which is responsible for connection setup, for example a basic network switching centre comprising an intelligent network service switching function. To provide an intelligent network service, the switching function contacts the intelligent network service control function when it detects a predetermined event.
Conventionally, control in an intelligent network is thus based on services conforming to a standard and on a mechanism and an interface conforming to the same standard built into the node that comprises the switching function. The number of various intelligent networks standards is growing, and another current development trend is the increase of customized services. For example, the pan-European GSM (Global System for Mobile communications) comprises a large number of standardized services, but considerably fewer standardized services are being planned for the so-called third generation mobile communications systems. This allows operators and service providers to also compete on the basis of the service content. New service architectures employing an intelligent network-like control, such as OSA (Open Service Architecture), are also based on openness. It seems at the moment that the number of both standardized intelligent network-like protocols and proprietor-specific intelligent network-like protocols is on the increase.
A problem with the prior art solutions is that the node comprising the switching function must include a mechanism for each different intelligent network-like protocol, or service type, for example to ensure that the system will be prepared to activate a service in connection with call setup and that the service is activated if an activation event is detected. In addition to the mechanism, new interfaces need to be defined as well. This is complicated and makes it difficult and laborious to add new service features.